The slope of a line is calculated using the following formula:
Slope = (y2 - y1) / (x2 - x1)
where (x1, y1) and (x2, y2) are the coordinates of two points on the line.
In this case, the two points are (1, 1) and (-3, -4). So, the slope is:
Slope = (-4 - 1) / (-3 - 1) = -5 / -4 = 1.25
Therefore, the slope of the line is 1.25.